1. Field of the Invention
The present invention, a musical instrument tuner, relates to the measurement of the frequency (also called pitch) of a musical note played on a musical instrument, and optimum display of that information for use by the musician in tuning the instrument.
2. Description of the Prior Art
A musical instrument tuner (or hereafter referred to as simply a tuner), is intended to assist a musician in tuning a musical instrument. A tuner indicates in some way the deviation in frequency of a musical note from a predetermined frequency. Many such devices have been invented and many patented, and the patent space is replete with examples of various forms of this basic function. A survey of the prior art follows.
Tuners today have one characteristic in common, that being extensive informational displays. Typically tuners display the identity of the note being detected (‘A’ through ‘G’, with sharp and/or flat symbols), whether the note is fractionally sharp, flat, or in-tune, and other information related to the mode of operation of the tuner. Such modes may include manual vs. chromatic operation, selection of optimized tuning systems for fretted instruments, and display of non-tuning-specific information such as chord charts. Low battery indicators are common. Many tuners incorporate complex liquid crystal displays (LCDs) for user interface. Even tuners with so-called minimal displays have multiple light emitting diodes (LEDs) for display of the note being tuned and its sharp, flat, or in-tune status.
Kulas (U.S. Pat. No. 6,653,543, which issued on Nov. 25, 2003) teaches an elaborate display and control system with multiple modes of operation for various types of instruments. Nonstandard tunings (used by a minority of guitar players) are accommodated, as are non-tuner features such as chord chart and song list display. The invention encompasses analog to digital conversion of the instrument signal for external consumption, presumably by audio equipment. A metronome display is also included. Kulas starts out with a statement about versatile prior art tuners, stating, “While this versatility ensures that one model of tuner can be used for many different purposes, some users desire a more customized tuner with a display better suited for their particular needs.” Kulas' thrust is that tuners are sometimes too feature-rich for use by one musician with one specific instrument, and this is true. However, Kulas goes on to describe a preferred embodiment with a pivoting color display screen (FIG. 1A, showing letters EADGBE) that is nearly as overcomplicated as the prior art, for tuning purposes. For example, it is totally unnecessary to display two ‘E’ characters since the two E notes on a guitar are two octaves apart. There is no danger of confusion, that is, of the guitar player tuning the low E string two octaves high or tuning the high E string two octaves low. This extra ‘E’ results in obviously wasted display space and higher cost. Similar wasted space is apparent for the “drop-D” tuning example given (FIG. 5A), where there would be two ‘D’ letters displayed (DADGBE).
Hine, et al. (U.S. Pat. No. 6,291,755, which issued on Sep. 18, 2001) teaches a tuner which is mounted in the interior of an acoustic guitar, visible to the player, with a digital display indicating which note is being tuned (alphabetically) and whether the note is sharp, flat, or in-tune.
Merrick, et al. (U.S. Pat. No. 5,936,179, which issued on Aug. 10, 1999) teaches a multi-element display consisting of lights for each note of the twelve note western musical scale, in addition to sharp, flat, and in-tune indicators.
Merrick, et al. (U.S. Pat. No. 5,854,437, which issued on Dec. 29, 1998) teaches a multi-element LED display with sharp and flat indicators (see Merrick, et al., FIG. 3). Thus, there is a finite window in the frequency domain corresponding to the in-tune indication of each LED for each string.
Wittman (U.S. Pat. No. 5,637,820, which issued on Jun. 10, 1997) also teaches a multiple LED display in a guitar tuner. One such tuner is advertised on a web site for sale. It requires considerable technical skill for installation and does require alteration to the instrument (changing a potentiometer), though the literature says otherwise.
Steinberger (U.S. Pat. No. 5,549,028, which issued on Aug. 27, 1996) teaches an alphabetic display in a guitar tuner, as does Adamson (U.S. Pat. No. 5,070,754, which issued on Dec. 10, 1991). Adamson's invention additionally displays the octave in which the note falls.
Each of the references cited, as well as many other tuner patents, describe an extensive display consisting generally of detected note displays and sharp, flat, and in-tune indicators. These displays are unnecessary, wasteful and costly, and are unneeded by many musicians.
A particular feature of extant musical instrument tuners is an in-tune indicator, which will be examined in detail herein. This is typically an LED or LCD which gives the user an indication that the pitch is one of: Fractionally sharp, flat, or in-tune. In addition to the patents cited above which teach this feature, numerous others exist. For example, Rosado (U.S. Pat. No. 4,018,124, which issued on Apr. 19, 1977) teaches a sharp, flat, and in-tune LED display system that operates on a per-string basis on a guitar. When a string is in tune, an LED is lit, and sharp or flat conditions cause the LED to be extinguished. Merrick, et al. (U.S. Pat. No. 5,936,179), cited previously, and Capano, et al. (U.S. Pat. No. 4,163,408, which issued on Aug. 7, 1979) teach three-state indicators.
Pogoda, et al. (U.S. Pat. No. 4,365,537, which issued on Dec. 28, 1982) states, “If the frequency of the vibrating string is too high, diode 64 is energized and if the frequency of the vibrating string is too low, diode 66 is energized. The tension on the string is then adjusted until it is brought into tune.” This describes sharp and flat indicators, but also clearly implies a third in-tune region which is high but not “too high,” and low but not “too low.”
Milano (U.S. Pat. No. 6,465,723, which issued on Oct. 15, 2002) teaches a motor-driven tuning method, and it also uses a three-state in-tune criteria and display. Two of the display states are visually identical (flashing red light), but the display and frequency discrimination logic exhibits three distinct regions of measurement: Flat, sharp, and in-tune.
Long, et al. (U.S. Pat. No. 6,184,452, which issued on Feb. 6, 2001), regarding another automated tuning system, teaches a “closed loop tuning control means . . . arranged to receive said comparison signal and automatically control operation of said adjusting means (5) until said comparison signal indicates that the frequency of said electrical signal is substantially equal to said predetermined frequency,” which is also a three-state discrimination of frequency. Wynn (U.S. Pat. No. 5,886,270, which issued on Mar. 23, 1999), another automated tuning system, discloses in the flowchart of FIG. 18 discrimination of “low,” “high,” and in-tune states.
Green (U.S. Pat. No. 6,791,022, which issued on Sep. 14, 2004) also recounts the prior art of three-state indicators by stating that tuners may “employ a frequency-measurement circuit that detects the primary frequency of the plucked string and indicates, usually on a visual display, whether the string is tuned high, low, or on key.”
A vibratory indicator system is taught by Kaufman (U.S. Pat. No. 5,883,323, which issued on Mar. 16, 1999). This system, too, includes a three-state indicator: “Musical notes from the instrument, hereinafter referred to as “tuning notes”, are “in tune” when within an acceptable tolerance range of acoustic pitch determined by the tuner.” This language is used throughout Kaufman. A prototype described by Kaufman utilizes a commercially available tuner which includes a three-state tuning indicator with the vibrator controlled indirectly by the in-tune indicator's electrical signal.
Freeland, et al. (U.S. Pat. No. 6,066,790, which issued on May 23, 2000) teaches a multi-frequency tuner with a comprehensive display. Of particular interest is the statement: “The magnitude of the deviation can be generally indicated, for example by the number of lights illuminated. The display can be limited to indicating whether the measured frequency is sharp or flat with appropriate symbols or colored lights.” The second sentence would seem to imply a two-state indicator, except it is made in the context of the previous sentence which is discussing the “magnitude of the deviation.” This forces us to conclude that the second sentence suggests a modification of the means of displaying frequency deviation, with one or more lights or symbols on either side of the in-tune indicator.
Campbell (U.S. Pat. No. 5,777,248, which issued on Jul. 7, 1998) teaches a binary sharp/flat indicator in conjunction with a strobe tuning display. The text states that “The sharp/flat indicator provides for gross tuning to within range of the strobe display.” The sharp/flat indicator is not intended to be used as a fine tuning device, and in fact Campbell states that fine tuning should be performed using the stroboscopic display. The display in its entirety is interpreted as a three part indicator: Coarse sharp, coarse flat, and degree of mistuning.
It is seen that this mode of operation of tuners, (sharp, flat, and in-tune or frequency deviation indicators) is the norm and is an assumed and unchallenged feature and function that designers of musical instrument tuners automatically incorporate into their designs and teach in the prior art without forethought and without any suspicion that a simpler mode of operation would be better. All the prior art references cited suffer this deficiency.
Another common tuner feature is a display indicator of the proportional deviation of the sensed note from a reference pitch, such as a mechanical or simulated meter movement (see Ridinger, U.S. Pat. No. D378,683, which issued on Apr. 1, 1997), or lights that flash at varying rates as a function of such deviation, or directional arrows on an LCD that are displayed as a function of such deviation, as in Kondo (U.S. Pat. No. 6,965,067, which issued on Nov. 15, 2005), Risch (U.S. Pat. No. 4,041,832, which issued on Aug. 16, 1977), and Steinberger (U.S. Pat. No. 5,427,011, which issued on Jun. 27, 1995). This display form is only useful to the vast majority of musicians to provide binary sharp/flat information; that is, telling them whether the instrument is sharp or flat. The cheap, uncalibrated nature of these tuner displays renders the scale markings practically useless, where present. The inventor has in the course of his work tested numerous commercial tuners and has found this to be the case. Displays consisting of blinking lights or arrows are of little value because the user cannot relate the blinking rate to a certain pitch deviation. For example, Wittman (U.S. Pat. No. 5,637,820, which issued on Jun. 10, 1997) discloses a blinking LED: “Thus, if the pitch is 20 cents sharp, the right LED would blink eight times per second.” There is likely no user who could take this information and accurately judge a pitch error. Elimination of these features saves cost and display space, and the user does not miss them.